Apparatus for truing grinding wheels



T. BARISH APPARATUS FOR TRUING GRINDING WHEELS Filed Nov. 27,

Aug.- 30, 1932.

Patented Aug. .30, 1932 PATENT Price THOMAS BARISH, or JAMEsrowN, new YORK APPARATUS non 'IR'UING GRINDING WHEELS Application filed November 27, 1928. Serial No. 322,170.

This invention relates to grinding wheels, and particularly to grinding Wheels utllized in the forming of raceways of ballbearlngs.

It is desirable to form such raceways with compound curves in transverse cross section, that is, to have difierent curves forming the opposite sides of araceway. For example, such curves may, in transverse'section, be circular arcs having centers of curvature spaced apart in a direction transversely of the raceways, and with the radii of curvature of the two curves crossing or intersecting. Such raceways have heretofore been difficult to form, but may be formed by grinding the same to the desired shape by a grindinglwheel or disk whose peripheral edgein transverse cross'section corresponds to the two transverse sectional curves of the raceways.

An object of this invention isto provide an 2 improved method and apparatus for forming the desired curves upon the periphery of the grinding wheel, and which will be relatively simple and practical.

A further object of the invention is to provide an improved apparatus for truing the edges of a grinding wheel or disk to the de:

sired compound curves, with whichthe radii of curvature of two curves and the distance between the centers of curvatures of two curves may be varied, with which adjustment for wear on the grinding wheel may be made, and which will be relatively simple, compact and inexpensive.

Various other objects and advantages will 7 be a Jparent from the following description of an embodiment of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claim.

In the accompanying drawing Fig. 1 is a plan of the truing machine, constructed in accordancecwith this invention;

Fig

. 2 is an end elevation of the same, with i two parts partly broken away to better show other parts; and r Fig. 3 is a diagram illustrating the operation of the tool upon the wheel periphery.

In the illustrated embodiment of the 1nvention, the grinding'wheel 1, whose periphextends, into proximity to cry is to be trued or provided with a compound curve, is mounted in any suitable manner' upon a shaft, which in turn is rotatably mounted in suitable bearings 3 and driven in a suitable manner, such as by a pulley 4 mounted on the shaft and operated b a belt from any suitable source of power. he bearings 3 may extend from a suitable base 5 having guidew'ays 6 uponits upper face and eXtendin parallel to the shaft 2. t r A carriage 7 is mounted upon the base '5 and guided in movement by the guideways 6. The movement of the carriage along the ways 6 may be effected, and the carriage'secured inadjusted positions, in any desired manner, such as by lugs 8 on'the base';5 and screws 9 which pass through the lugs 8 and cooperate with the carriage 7 to move or secure it. The carriage 7 is provided with guides 10 which extend crosswise of the ways 6 and slidingly mount a plate 11.

A suitable operating screw '12 passing through a lug or car 13 on the carriage and engaging with the plate serves as a medium to shift the plate backand' forth along the guides 10, and hold the plate in different adjusted positions. The plate 11 is provided with an arcuate strip 1l, thearms of which extend from opposite sides of the plate and at their free ends are attached to the forward end of the plate 11 by a cross strip. 15.

A table 16 is pivotally attached, such as by a pivot screw 17,-tothe plate 11, so that the tableimay swing or oscillate sidewise, duringwhich movement it will be guided by the arcuate strip 14. The table in turn is provided with guides 18 which extend ra-' ,dially toward and from the axis of the pivot screw 17, and a tool block'19'is mounted in 'the guides 18 for movement therealong. A

screw 20 cooperates with the table and the block to shift the block alongthe guides 18 of the table and hold the block in adjusted positions.

s A suitable secured upon the upper face of the block 19 in any suitable manner, such as by screws 22, and the working edge or nose of the tool the periphery of the grinding wheel 1. c I

forming tool 21 is removably Assuming that the grinding wheel is being rotated through its shaft 2, the forming tool 21 is attached to the block 19, and the latter is adjusted until the working edge of the tool is at a distance from the extended axis of the bearing screw 17 corresponding to the corresponding radius of each curve. The screws 9 are then adjusted to place the'pivot screw 17 at one of the desired centers of curvature, such as at one side of the other of the central plate of the grinding wheel and at a distance therefrom corresponding to the desired lateral displacement of "the center of curvature of the desired curve from that plane.

The table is theno-scillated' about the-screw 17 and the screw 12 operated to shiftthe plate 11 until the tool 21 engages with the peripheral edge of the grinding wheel. Thereupon the oscillations of the table will be efi'ected between the positionshown in Fig. 1 and'one side of that position, back and forth until that side of the peripheral edge of the grinding wheel has the desired curvature.

Thereupon the screws 9 are operated to shift the carriage in a direction parallel to the shaft 2, a distance corresponding to the desired distance between the centers of curvatures of the two curves on opposite sides of the periphery of the wheel, and thereupon the table is again oscillated to true up or form the other side of the peripheral edge of the'grinding wheel ina similar manner.

The operation is illustrated diagrammatically in Fig. 3,in which the paths of travel of the working edge or nose of the tool 21 is illustrated by the curves A and'Bsho'wn "extended in dash lines in that figure. The

center of curvature ofthe curve A is' represented at O, and the center of curvature of the other curve B is represented at C. Similar curves A and B are separately illustrated with larger radii in the same figure, in order'to illustrate more clearly, the re lation between the curves Aand B.

It will be noted that the two' centers "of curvature C and C are spacedapart'in -a of and an equal distance from the central plane of the grinding wheel.

The centers of curvature C and C will successively lie in the extended axis of the bearing or pivot screw 17, and thus the center ofos'cillation of the tool 21 will be shifted from one center of curvature to the other by the'shifting of the pivot screw 17 in a "direction parallel to the shaft'Q.

Itwill be observed thatthe truing or forming or the compound curveaipon the'periphery of the grinding Wheel may be thus obtained in a simple and practical manner, and variations in the compound curves thus formed on the grinding wheel may be obtained by simple adjustments.

As the diameter of the wheel 1 decreases through use, the screw 12 may be operated to shift the=plate11 toward the wheel, and carry the tool into re-engagement with the grindingwheel, and thus take care of wear on "the grinding wheel.

, It will be understood that the apparatus illustrated is capable of various modifica tions within the principle of the invention,

grinding wheel,mefans'i or laterally moving said carriage relatrve'ito 'sald base,'ia plate slidably mounted on'asaid carriage for-movement toward and from said, grinding wheel,

an arcuateguidestrip'mOunted on one end of said M plate, a table pivotally mounted on the other end of said; plateysaid Ztab'le having its free end guided-bysaidarcuated strip, and a trimming toolmounted on'said table for "trimming the peripheral edge of the grinding ;'wheel by movement across and z in contact With th'e edgeaofzthe'wheel;

. THOMlii-SpBARISH.

area

was 

